May 25, 2021
View at EarthSky Community Photos. | Early on the morning of May 23, 2021, Angus Weller spotted these Kelvin-Helmholtz clouds over the Coastal Mountain Range just north of Vancouver, British Columbia. Angus said: “It’s only the 2nd time I’ve seen this cloud formation.” Thank you, Angus!
Clouds that look like waves are rare and beautiful. These clouds – known as Kelvin-Helmholtz clouds, billow clouds, or shear-gravity clouds – might have been the inspiration for Van Gogh’s painting Starry Night. The next time you spot one of these remarkable wave clouds, capture a photograph and send it to us!
Kelvin-Helmholtz clouds are named for Lord Kelvin and Hermann von Helmholtz, who studied the physics of the instability that leads to this type of cloud formation. A
The fact is, when you gaze toward any horizon, you’re looking through
more air than when you gaze overhead. It’s this greater quantity of air that causes oddly shaped suns and moons. At zenith (straight up) the atmosphere will be at its thinnest. That’s why professional astronomers prefer to observe their objects of interest as high up on the sky as possible (and as their telescopes allow), to diminish the effects of any atmospheric distortion lower in the sky.
No matter where you are on Earth, as you look toward a horizon, you’re looking through more atmosphere than when you look overhead. Image via Phil Plait.